Improvements in working blast-furnaces



Pla ha I FURNACES.

IMPROVEMENTS IN WORKING BLAST Baum JUL 25 1871 INVENTUR: HENRY BESSEMEB.

Witnesses{ UNIT D STATES HENRY BESSEME'R, 0F LONDOX, ENGLAND.

mum n cuusmucnnu AND MODES or wnmmlav BLAST-FURNACES.

Specification forming part of Lettens Patent No. 117,246,1lated July 25, 1871.

To all whom it may concern:

Be it known that l,- Hnsnr Bnsslsmnn, of Queen Street Place, Cannon street, in the city of Londolna subjectof the Queenof Great Britain, have invented or discovered new and uselul-f lmprovements in the construction and mode of working blast-furnaces employed for smelting the ores of iron, and in the mode of employing and utilizing the gaseous products of such fur,

nnces, and also in the construction and mode of working blastfengines employed to force'alr into blast and other furnaces; and l, the said HENRY Bfissfizium, do hereby declare the nature of the said invention, and'in whatmanner the same is to he performed, to be particularly described and ascertained in and by the following statement thereon-that. is to say:

The outer shell or case of the furnace, which, for t-he purposes of my in rention, 1 make of very strong plate-iron or steel, and which extends from oelow the bottom of the hezuth up to the crown or top of the furnace, there uniting with the metal ring which forms the mouth of the furmace, and thus incasing the whole of the lirebrick or stonework which constitutes the furnace, suitable openings being left in the shell for the purpose hereinafter referred to, l prefer to ma her] is shell in separate rings or sectionsnnitcd by stout flanges, by means of which the several portions are firmly united, the whole being, as tar as necdml, strengthened by hoops, angle-ribs,

01 T-irons securely riveted to the plating, the.

general structure being further supported on castiron or riveted platc iron' columns surrounding the lower part, all the joints of the shell being well calkcd and capable of rosistin g an internal pressure of twenty or more pounds per square inch on the whole internal surface of the furnace. lntothis furnace 1 force air by a suitable blast.-

engine through several t yeres or openings used ure blast-flu'nace. The method in which I prefer to confine the gases in the furnace until sufiieient )ressure is attained is hereinafter described. in consequence of the pressure thus employed the temperature of the gaseous products of combustion will be great] y increased, and lam thereby enabled to dispense with the whole of stoves, pipes,- and furnaces generally employed for heating the blast, although the higlupressure blast-furnace may, if desired, be worked with hotinstead of cold blast. in some cases it may be found desirable to lower the temperature of the gaseous products of combustion alter they have left the blast'furnace. To some extent this may be done by causing the hotgaseous products to envelop 'or come in contact with the pipes which convey the bio st to the furnace, and tho 5 a certain amount of heat may be readilytransmitted tot-he air cir-, culating through them. The arrangements for feeding in the fuel, ore, and fluxes at the top of the furnaces-must be such-as to cli'cct this object without allowing much of the gases to escape if the cup and cone arrangement be employed, or if a piston he used in lieu thereof to close the furnace. I, in either case, continue the sides of the cup vertically upward, fo'rmin g thereby a strong plate-iron cylinder having a cover into which another cone or piston is fitted, thus mall ing the cylinder :1 close chamber. A feedinglloor or stage may he made at alevel with the upper cone or piston-valve. Vlhen feeding the furnace 1 lower the upper valve and put the requisite charges of ore and fuel into the cylinder and then close the upper valve, after which I open the lower one and allow the material to fall into the furnace, thus loosing a cylind r-full of the compressed gases at everysueh discharge of fuel into the furnace. The. joints of'the cone or piston-valve or other joints may .be prevented from leaking gases outwardly by the employment of air or steam of greater pressure introduced be tween the joints or valve-fittings, and the metalwork constituting all such valves, cones, or valves'eats may be kept from injury by heat by coring or otherwise forming therein passages for the cireulation of water. b'uch parts may also be made to receivev less heat by conduction by using thin fire-tiles or other slow conducting materials between the flanges, which unite them to other parts, which are unavoidably made very hot. My

invention also consists in cconomizing fuel in' flow by a pump attached to the blast-engine, whereby the quantity of water injected may be regulated. By this-means the'highly-heated gases may be cooled down and mixed with steam arising from theevaporation of the injected shower of water.

For the purpose of forcing the blast into highpressure fumaces when used for smelting iro'n' ores,,as in the invention herein described, and also when employed for forcing blastunder pressure into furnaces employed in fusing malleable or wrought-iron and steel and other carburets of iron, I employ the gaseous products of such highpressure furnaces when cooled down with water or otherwise, for giving motion to u hot-air-blast engine, in which the said gaseous products (in combination with the steam produced in the cooling process) are made to act in a direct-acting blast apparatus. I prefer to arrange the air-cylinder and the gas-cylinder in a-line with one piston-rod connected to both pistons. I prefer to use either piston-valves or double-beat equilibriumvalves both' for the air and gas-cylinders, each of which I line with a plain shell of hard metal, so made and fitted in between the covers as to readily be removed and exchanged for a similar one when too much worn for use. The air so forced is conveyed into -21 receiver having two diaphragms dividing it into three compartments which communicate with each other by small openings audthustond muchto equalize the blast. A fly-whcclund crank are employed to regulate the motion of the engine, and one or more valves are employed to regulate the pressure ofthc gases and prevent thc pressure from exceeding-the proper limit. It will thus be seen that the highw pressure furnace, to whatever purpose it is applied, may be supplied with blast at the pressure.

desired without employing boiler-power and i'ucl for that purpose, the high-pressure i'urnacc itscli' furnishing all the power necessary for this purpose without burning the gas in other iurnaccs to obtain power through the agency ofstcam. The escaping carbonic-maid gas/from the lower part of the furnace may be conducted also tothc blast-cugine,orit may be used to work the wind ing-cngine, or the heat thus escaping may he cmpioycd to burn the lime or roast. or drythc orc or fuel employed.

And in order that this mode of constructing and working blust-furimccs may be fully under- -stood, the same is represented in vertical section at Fig. l, and in elevation at. Fig. 2. Fig. 3 is a cross-section taken at two different heights 0n the crooked line A B. Fi 4 is avertical section of the pipe for conveying the furnace-gases to the blast-engine.

The same letters are used in each figure to denote a repetition oi'tliat part.

a is the outer shell or casc of the furnace, which incloscs the whole of the masonry or brick-work. This case may be further strengthened by hoops or angle-flanges of iron or nice] so as to render it capable of withstamling sai'cly internal pressure from one or two atmosphcrcs in excess ofthccxternal atomsphcric pressure. The slope of the bushes is similarly ineuscd in a cone of platcmetah'a', the base of the cone being further chamber, c,'is inclosed around the boshes, the

partitions a dividing this space into two cha-mhers, c and c". A strong box-girder, II, with central web, extends entirely around theunder side of the outer wall of the furnace, andat intervals .rcsts on strong; iron-webbed columns 0, which occupy thechamber c, resting below on the bed or foundation of masonry f1 Two small ante-chamhers, y and h,are made with two doors, each for the purpose oinfl'ording entrance and exit for the \vorkmcn from and into the chambers c and a at all timcs,\vhcn required. Notwithstanding, the air in these chambers isgreatly in excess oi the external nhuospheric pressure, and whiclrmodc oi gaining access to and egress from chainber is fully described in upatent in England bearing cven date herewith and numbered 1,432, and consequently docs not form part of thcprescutinvcntiou. Below the level of the tymp I form an nn'hcd cluuubcr, i, into which a truck or carriage can bc moved on rails for the purpose of receiving thc cinder flowing from the furnace, or thecast of metal may be run into amovable rcccptaclc so placed. The clunubcr i is provided with a well-fitted sliding door, made as near asmay be air-light; a little leakage of air from the chambcr i is prcii'rnblqas it will causc' an outward flow ol'niri'rom thcchamlwrc through the holc j and thus prevent the ascent of licatcd fumes from the chamber -z'. An annular flue, m, is formed around the furnace, into which sevcral passages, 11, load from the tlumac'e. At any part of the iluc m a rcstrictcduoutlct may be made of such asize as will allow thedesiredamount of ca'rbouimu-id gas to cscapc,whilc the rcst oi'the gas passes upward and is converted intocarbonic oxidc,and in that state dcoxidizes theorc, but without taking up as much carbon as the whole of the gases would do it'allowcd to pass upward among the fuel. The area oithccscapeopcnlugs n is cucll so greatly in excess of'thc area of the one restricted oath-t as to cause a very slow and gentle current of gas,to pass up them, and thus nottcnd to carry out any fuel by those passages. Man-holes for clearing,- out dust,it'ncccssary,can be made in the flue m,a'nd it found desirable that portion of the carbonic-acid gas allowed to escupc by tin-so passages from the iurnace'may be taken ofi'ar a much lower level than that shown in the drawing, the outlets olivine in that case much nearer to the level of the layers and communicating with a. passageor passages which pass out through the chamber c. At the top of the furnace .l have shown a cup-valve, p, which forms thc lower portion of thc chamber q, The upper part olthis chamber is fitted with a second cone, I, through the coon-col which thc rod a; of the conc p passcs, the cone 1' having a jointed sling to support ll. and allow it to bc balanced in the usual way and raiscd or lowered as rcquircd; the cone. 1) barring a separate arrangementof thc some kind, so that. each ofthc cones p and .cone r. of. these valves should be moreperfect than ansual, themetal parts being defended, f necessarykfiomsthefiaction of escaping gases by the which means the materials will fall into the furnace; The raising of the cone p and the lowei 'ing of the cone ravill allow another charge to enter the chamber, and so.on, a chamber full at as being allowed to escape at operationof "I v onld-iobserve' that in all cases before the cone is lowered an equilibrium of pressure must be efleeted between 'tba'chamber q and the in-: .side of l the furnace. For this purpose a valve,

Knot shown in the drawing, is provided by meansof which the workmanh may admit t e furnace gases or steam into cha ber 9 and thus equalize the pressure:- ve and below the cone 9'; and so,'als6', before lowering'the cone 1', he

allow such steam or gases to escape by a. valve into the external atmosphere, in that case.

equalizin the pressure above and below the t is desirable that the fitting-surfaces ge'ofsteam into the joint in-a manner similari'o tha't by which the leakage of flame .and heated gasesisj prevented from escaping from the'doors of high-pressure melting-furnaces,

by the ;use of air under pressure,-. as fully de.

scribed in a patent granted to me in- En'glahd, and hearing date the lilthday of November, 1868, and numbered 3,419; The gases, after passing upthrough the materials in the fimiace,

. findtheir escape by the openings t, and ,pass

into an annular channel, 41-, and from thence into .a large pipe, .10, shown in vertical section at Fig.

4, where a portion of the side of the furnace is also shownto render the positionof the pipe 10 and its connection with the'channel u'more clearly understood. The' pillow is lined with segmental fire-bricks w, in order to defend ;the

outer iron shell' from the efl'ects of beau-and alsoto prevent loss of pressure in thetgases and vapors by the radiation ofheat therefrom. A forcepump, worked by the blastenginc, forces water 7 to the top of the pipe 10 by a pipe. wh ch passes through-top of the pipe 10 at w, having a rosehead, v, perforated in such a way' as to cause water forcedjthrough it tefall in a shower down the pipe w for the purpose of lowering the temperatnre of the; fiirnace-gasesto a point suitable for the hot-air engine to be driven by them; and, although I prefer a direct-acting blast-engine, as before named, it will nevertheless beobvious that any'efiicieiit planof blast-engine may be used, the ordinary steam-cylinder or which, will .be supplied with waste gases mixed with the steam generatedb them trom the falling shower ofwater sujch cyl der being'in all'cases of sufticient sired extent 5 the volume of steamand gases al ways being in excess of the volumelot' air and water injected, by reason ofthe expansion of the ismeter to compress the blast the de-.

air by the heat'of the furnaoc'andthe'formation of steam from the falling shower of water.

.And although I have described the working. of the blast-filrnace under the pressureof conlined gases, I desire it to be understood that certain parts ofmysaid improvements are equally applicable to blastfurnacesworking with open tops, and .fiu naces where -,th e wastegases. are collected for combustion in hot air stoves or under boilers. These-improvements consist in the mode, shownsnddescribed, of allowing an outtlowjofta portion of the carbonic-acid 'gas a short distance from the toy and also the continuous flow of metal and cin or from the furnace.

fl-Having described my invention, and the way in which it may be carried into practical operation, Idesire it to be understood that I do not confine myself to the precise details here given, provided that the character of my invention be retained; but

.-I claim-as my improvements in the construc tion and mode of working blast employed for smelting the ores of iron, and in the mode of employing and utilizing the gaseous products of such furnaces, and also in the conemployed to force air into blast and other fur- 1. The entirely enveloping them'asomy or brick-work of'a blast-furnace in-a'sirong air-tight pressure. a 7 2. The inclosing'the boshes of 'blast-furnaces, so as to-have the tuyere-holes opening externally into a large chamber accessible to'workmen containing air under pressure. v Q

- 3. The inclosing the tap-hole of blast-furnaces in alarge chamber capable of containing air under pressure,- so-that the pressure ofgair therein may, when required, prevent escape of -flame thereat. r

' 4. The providing outlets'fioma'blast-furnace cansed to pass through and work such engine, and thereby actuate the pumps which supply the blast to the furnace. HENRY BESSEMER.

Witnesses:

\ G. F. Warm,

Tnos. Bnown; Both pf No. 17 Gnwoohurol; Landon.

struction and mode of working blast engines case or jacket, to. admit of the gaseous products of combustion being retained under considerable near. the tuyeres for *the escape of a portion of nor that the gases issuing from such fiu-usce m 

